The present invention relates to an analog-to-digital converter.
The invention of this type has heretofore been proposed comprising, as shown in FIG. 2, an adder or a subtractor 3 which adds or substracts an input signal from an analog signal input terminal 1 and an analog output from a D/A converter 7, an amplifier 4 for amplifying the analog output of said adder or said subtractor 3, an A/D converter 5 which converts the analog output of said amplifier 4 into a digital value, and a processor 6 which reads the digital output of said A/D converter 5 and which determines a digital output for said D/A 7 converter.
According to the above-mentioned prior art as is widely known, there is no guarantee that a bit width of the D/A converter at a minimum resolution is maintained perfectly uniform. Namely, any variance in the bits from the D/A converter is amplified through the amplifier, and the continuity of data is lost in the final output of the A/D converter.